Maltooligosaccharides from JEG-3 trophoblast-like cells exhibit immunoregulatory properties.

PROBLEM: to better understand the immunoregulatory properties of trophoblasts, we have searched for small immunologically active carbohydrates derived from intact trophoblast-like cells. METHOD OF STUDY: using solid phase extraction coupled with HPLC and mass spectrometry methods, we have characterized a low molecular weight carbohydrate-rich fraction associated with JEG-3 cells. We have also tested the bioactivities of selected authentic oligosaccharides found in the oligosaccharide fraction. RESULTS: the most abundant components of the low molecular weight carbohydrate-rich fraction were maltotriose and maltotetraose, with detectable amounts of maltopentaose. When authentic maltooligosaccharides were tested using lymphocytes, IL-2 inhibition was observed. This activity was dependent upon the number of saccharide subunits, stereochemistry, and concentration. To further test maltooligosaccharide properties, maltopentose was attached to glass cover slips. Although spontaneous neutrophil motility was observed on unmodified and control surfaces, it was inhibited on maltooligosaccharide-derivatized surfaces. CONCLUSION: maltooligosaccharides are associated with the trophoblast's surface where they may exhibit immunoregulatory activities.